• ABIOSDSK.386: 32-bit disk access for your PS/2's MFM and ESDI drives

    From Josh Rodd@joshua.at.rodd.dot.us@rodd.us to comp.sys.ibm.ps2.hardware on Sat Aug 8 02:48:43 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    Presenting ABIOSDSK.386: 32-bit disk access finally gets here for your
    PS/2 with gigantic, clanking MFM drives and irreplaceable ESDI drives.

    This has been about 35 years in coming, ever since as a sprightly 11
    year old I was miffed that my fancy PS/2 P70 just wouldn't let me click
    the "32-bit Disk Access", despite me barely understanding what was even
    for. Of course, we now know that that means you can do things like open
    a couple DOS windows on your 2MB machine and listen to the fixed disk
    (or, more likely, a hard drive, since this wasn't happening on real IBM computers with real IBM fixed disk adapters/A) thrash like crazy.

    Nonetheless, here it is. It is based on IBM2ADSK.ADD from the OS/2 DDK
    and WDCTRL from the Windows 3.1 DDK. So far, testing has been really
    thorough: I tested it on 86Box with a Type 2 Model 80, ESDI adapter
    card, PC DOS 3.30, 4MB and 2MB configurations, Windows 3.1. A test suite program is included which tries to really exercise the disk and get
    Windows' multitasking really crankin' with a couple DOS windows open.

    Download it for yourself at:
    https://github.com/sbooks-org/ABIOSDSK386
    Direct link for 720kB floppy image, because how else would you get it on
    your PS/2? https://github.com/sbooks-org/ABIOSDSK386/releases/download/v0.90/ABIOSDSK.IMG

    No warranty is implied, particularly given this is the kind of code
    whose failure mode will mean you get to reformat your fixed disk and
    reinstall everything.

    I plan to do SCSI support next (it's easier than it sounds; it's just
    another ABIOS interface). Can someone remind me what the state of
    Windows 95 support for ABIOS disk adapters (MFM, ESDI, etc.) and the
    PS/2 SCSI adapter is?
    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Louis Ohland@ohland@charter.net to comp.sys.ibm.ps2.hardware on Fri Aug 7 22:06:38 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    Unal Z and WBST snuck out for some really good smokes. They aren't
    taking any text messages.

    https://ardent-tool.com/utils/#Win_Utils

    SPOCK206.ZIP SPOCK206 Driver for Windows 95/98 by Unal Z (info) https://ardent-tool.com/IBM_SCSI/spock206.html

    SPOCK2NT.ZIP SPOCK206 Driver for Windows NT by Unal Z (info) https://ardent-tool.com/IBM_SCSI/spock206.html

    AHA206.ZIP AHA-1640 Windows 95/98 driver by Unal Z (info) https://ardent-tool.com/SCSI/aha206.html

    Josh Rodd wrote:
    Presenting ABIOSDSK.386: 32-bit disk access finally gets here for your
    PS/2 with gigantic, clanking MFM drives and irreplaceable ESDI drives.

    This has been about 35 years in coming, ever since as a sprightly 11
    year old I was miffed that my fancy PS/2 P70 just wouldn't let me click
    the "32-bit Disk Access", despite me barely understanding what was even
    for. Of course, we now know that that means you can do things like open
    a couple DOS windows on your 2MB machine and listen to the fixed disk
    (or, more likely, a hard drive, since this wasn't happening on real IBM computers with real IBM fixed disk adapters/A) thrash like crazy.

    Nonetheless, here it is. It is based on IBM2ADSK.ADD from the OS/2 DDK
    and WDCTRL from the Windows 3.1 DDK. So far, testing has been really thorough: I tested it on 86Box with a Type 2 Model 80, ESDI adapter
    card, PC DOS 3.30, 4MB and 2MB configurations, Windows 3.1. A test suite program is included which tries to really exercise the disk and get
    Windows' multitasking really crankin' with a couple DOS windows open.

    Download it for yourself at:
    https://github.com/sbooks-org/ABIOSDSK386
    Direct link for 720kB floppy image, because how else would you get it on
    your PS/2? https://github.com/sbooks-org/ABIOSDSK386/releases/download/v0.90/ABIOSDSK.IMG

    No warranty is implied, particularly given this is the kind of code
    whose failure mode will mean you get to reformat your fixed disk and reinstall everything.

    I plan to do SCSI support next (it's easier than it sounds; it's just
    another ABIOS interface). Can someone remind me what the state of
    Windows 95 support for ABIOS disk adapters (MFM, ESDI, etc.) and the
    PS/2 SCSI adapter is?

    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Louis Ohland@ohland@charter.net to comp.sys.ibm.ps2.hardware on Fri Aug 7 22:08:21 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    Joshua, IIRC the FD MCS-700 had 32-bit BDA.

    Josh Rodd wrote:
    Presenting ABIOSDSK.386: 32-bit disk access finally gets here for your
    PS/2 with gigantic, clanking MFM drives and irreplaceable ESDI drives.

    This has been about 35 years in coming, ever since as a sprightly 11
    year old I was miffed that my fancy PS/2 P70 just wouldn't let me click
    the "32-bit Disk Access", despite me barely understanding what was even
    for. Of course, we now know that that means you can do things like open
    a couple DOS windows on your 2MB machine and listen to the fixed disk
    (or, more likely, a hard drive, since this wasn't happening on real IBM computers with real IBM fixed disk adapters/A) thrash like crazy.

    Nonetheless, here it is. It is based on IBM2ADSK.ADD from the OS/2 DDK
    and WDCTRL from the Windows 3.1 DDK. So far, testing has been really thorough: I tested it on 86Box with a Type 2 Model 80, ESDI adapter
    card, PC DOS 3.30, 4MB and 2MB configurations, Windows 3.1. A test suite program is included which tries to really exercise the disk and get
    Windows' multitasking really crankin' with a couple DOS windows open.

    Download it for yourself at:
    https://github.com/sbooks-org/ABIOSDSK386
    Direct link for 720kB floppy image, because how else would you get it on
    your PS/2? https://github.com/sbooks-org/ABIOSDSK386/releases/download/v0.90/ABIOSDSK.IMG

    No warranty is implied, particularly given this is the kind of code
    whose failure mode will mean you get to reformat your fixed disk and reinstall everything.

    I plan to do SCSI support next (it's easier than it sounds; it's just
    another ABIOS interface). Can someone remind me what the state of
    Windows 95 support for ABIOS disk adapters (MFM, ESDI, etc.) and the
    PS/2 SCSI adapter is?

    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Josh Rodd@joshua.at.rodd.dot.us@rodd.us to comp.sys.ibm.ps2.hardware on Sat Aug 8 03:10:38 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    Aha... I recall those drivers now, and they are state of the art.

    Was there ever an ABIOS disk driver for Windows 95? I know NT had one,
    called, well, ABIOSDSK.SYS.

    ABIOSDSK.386 should not be considered to be "high performance" just yet.
    It does its fair share of double buffering to avoid the pitfalls of DMA.

    Louis Ohland <ohland@charter.net> wrote:
    Unal Z and WBST snuck out for some really good smokes. They aren't
    taking any text messages.

    https://ardent-tool.com/utils/#Win_Utils

    SPOCK206.ZIP SPOCK206 Driver for Windows 95/98 by Unal Z (info) https://ardent-tool.com/IBM_SCSI/spock206.html

    SPOCK2NT.ZIP SPOCK206 Driver for Windows NT by Unal Z (info) https://ardent-tool.com/IBM_SCSI/spock206.html

    AHA206.ZIP AHA-1640 Windows 95/98 driver by Unal Z (info) https://ardent-tool.com/SCSI/aha206.html

    Josh Rodd wrote:
    Presenting ABIOSDSK.386: 32-bit disk access finally gets here for your
    PS/2 with gigantic, clanking MFM drives and irreplaceable ESDI drives.

    This has been about 35 years in coming, ever since as a sprightly 11
    year old I was miffed that my fancy PS/2 P70 just wouldn't let me click
    the "32-bit Disk Access", despite me barely understanding what was even for. Of course, we now know that that means you can do things like open
    a couple DOS windows on your 2MB machine and listen to the fixed disk
    (or, more likely, a hard drive, since this wasn't happening on real IBM computers with real IBM fixed disk adapters/A) thrash like crazy.

    Nonetheless, here it is. It is based on IBM2ADSK.ADD from the OS/2 DDK
    and WDCTRL from the Windows 3.1 DDK. So far, testing has been really thorough: I tested it on 86Box with a Type 2 Model 80, ESDI adapter
    card, PC DOS 3.30, 4MB and 2MB configurations, Windows 3.1. A test suite program is included which tries to really exercise the disk and get Windows' multitasking really crankin' with a couple DOS windows open.

    Download it for yourself at:
    https://github.com/sbooks-org/ABIOSDSK386
    Direct link for 720kB floppy image, because how else would you get it on your PS/2? https://github.com/sbooks-org/ABIOSDSK386/releases/download/v0.90/ABIOSDSK.IMG

    No warranty is implied, particularly given this is the kind of code
    whose failure mode will mean you get to reformat your fixed disk and reinstall everything.

    I plan to do SCSI support next (it's easier than it sounds; it's just another ABIOS interface). Can someone remind me what the state of
    Windows 95 support for ABIOS disk adapters (MFM, ESDI, etc.) and the
    PS/2 SCSI adapter is?



    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Josh Rodd@joshua.at.rodd.dot.us@rodd.us to comp.sys.ibm.ps2.hardware on Sat Aug 8 03:11:56 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    It sure did... FASTDISK, I believe. By the time I was an adolescent
    snotling, I acquired it along with an MCS-600 and finally got to click
    that 32-bit Disk Access button.

    Not that it really mattered since I spent most of my time booted into an
    actual 32-bit operating system (you know, the one that had all-16-bit
    disk adapter device drivers...)

    Louis Ohland <ohland@charter.net> wrote:
    Joshua, IIRC the FD MCS-700 had 32-bit BDA.

    Josh Rodd wrote:
    Presenting ABIOSDSK.386: 32-bit disk access finally gets here for your
    PS/2 with gigantic, clanking MFM drives and irreplaceable ESDI drives.

    This has been about 35 years in coming, ever since as a sprightly 11
    year old I was miffed that my fancy PS/2 P70 just wouldn't let me click
    the "32-bit Disk Access", despite me barely understanding what was even for. Of course, we now know that that means you can do things like open
    a couple DOS windows on your 2MB machine and listen to the fixed disk
    (or, more likely, a hard drive, since this wasn't happening on real IBM computers with real IBM fixed disk adapters/A) thrash like crazy.

    Nonetheless, here it is. It is based on IBM2ADSK.ADD from the OS/2 DDK
    and WDCTRL from the Windows 3.1 DDK. So far, testing has been really thorough: I tested it on 86Box with a Type 2 Model 80, ESDI adapter
    card, PC DOS 3.30, 4MB and 2MB configurations, Windows 3.1. A test suite program is included which tries to really exercise the disk and get Windows' multitasking really crankin' with a couple DOS windows open.

    Download it for yourself at:
    https://github.com/sbooks-org/ABIOSDSK386
    Direct link for 720kB floppy image, because how else would you get it on your PS/2? https://github.com/sbooks-org/ABIOSDSK386/releases/download/v0.90/ABIOSDSK.IMG

    No warranty is implied, particularly given this is the kind of code
    whose failure mode will mean you get to reformat your fixed disk and reinstall everything.

    I plan to do SCSI support next (it's easier than it sounds; it's just another ABIOS interface). Can someone remind me what the state of
    Windows 95 support for ABIOS disk adapters (MFM, ESDI, etc.) and the
    PS/2 SCSI adapter is?



    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Josh Rodd@joshua.at.rodd.dot.us@rodd.us to comp.sys.ibm.ps2.hardware on Sat Aug 8 03:12:10 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    It sure did... FASTDISK, I believe. By the time I was an adolescent
    snotling, I acquired it along with an MCS-600 and finally got to click
    that 32-bit Disk Access button.

    Not that it really mattered since I spent most of my time booted into an
    actual 32-bit operating system (you know, the one that had all-16-bit
    disk adapter device drivers...)

    Louis Ohland <ohland@charter.net> wrote:
    Joshua, IIRC the FD MCS-700 had 32-bit BDA.

    Josh Rodd wrote:
    Presenting ABIOSDSK.386: 32-bit disk access finally gets here for your
    PS/2 with gigantic, clanking MFM drives and irreplaceable ESDI drives.

    This has been about 35 years in coming, ever since as a sprightly 11
    year old I was miffed that my fancy PS/2 P70 just wouldn't let me click
    the "32-bit Disk Access", despite me barely understanding what was even for. Of course, we now know that that means you can do things like open
    a couple DOS windows on your 2MB machine and listen to the fixed disk
    (or, more likely, a hard drive, since this wasn't happening on real IBM computers with real IBM fixed disk adapters/A) thrash like crazy.

    Nonetheless, here it is. It is based on IBM2ADSK.ADD from the OS/2 DDK
    and WDCTRL from the Windows 3.1 DDK. So far, testing has been really thorough: I tested it on 86Box with a Type 2 Model 80, ESDI adapter
    card, PC DOS 3.30, 4MB and 2MB configurations, Windows 3.1. A test suite program is included which tries to really exercise the disk and get Windows' multitasking really crankin' with a couple DOS windows open.

    Download it for yourself at:
    https://github.com/sbooks-org/ABIOSDSK386
    Direct link for 720kB floppy image, because how else would you get it on your PS/2? https://github.com/sbooks-org/ABIOSDSK386/releases/download/v0.90/ABIOSDSK.IMG

    No warranty is implied, particularly given this is the kind of code
    whose failure mode will mean you get to reformat your fixed disk and reinstall everything.

    I plan to do SCSI support next (it's easier than it sounds; it's just another ABIOS interface). Can someone remind me what the state of
    Windows 95 support for ABIOS disk adapters (MFM, ESDI, etc.) and the
    PS/2 SCSI adapter is?



    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Louis Ohland@ohland@charter.net to comp.sys.ibm.ps2.hardware on Fri Aug 7 22:33:49 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    From a cursory surf, I'd say no.

    My SWAG would be looking at the NT miniport... Not what you wandted to
    hear...

    Josh Rodd wrote:
    Aha... I recall those drivers now, and they are state of the art.

    Was there ever an ABIOS disk driver for Windows 95? I know NT had one, called, well, ABIOSDSK.SYS.

    ABIOSDSK.386 should not be considered to be "high performance" just yet.
    It does its fair share of double buffering to avoid the pitfalls of DMA.

    Louis Ohland <ohland@charter.net> wrote:
    Unal Z and WBST snuck out for some really good smokes. They aren't
    taking any text messages.

    https://ardent-tool.com/utils/#Win_Utils

    SPOCK206.ZIP SPOCK206 Driver for Windows 95/98 by Unal Z (info)
    https://ardent-tool.com/IBM_SCSI/spock206.html

    SPOCK2NT.ZIP SPOCK206 Driver for Windows NT by Unal Z (info)
    https://ardent-tool.com/IBM_SCSI/spock206.html

    AHA206.ZIP AHA-1640 Windows 95/98 driver by Unal Z (info)
    https://ardent-tool.com/SCSI/aha206.html

    Josh Rodd wrote:
    Presenting ABIOSDSK.386: 32-bit disk access finally gets here for your
    PS/2 with gigantic, clanking MFM drives and irreplaceable ESDI drives.

    This has been about 35 years in coming, ever since as a sprightly 11
    year old I was miffed that my fancy PS/2 P70 just wouldn't let me click
    the "32-bit Disk Access", despite me barely understanding what was even
    for. Of course, we now know that that means you can do things like open
    a couple DOS windows on your 2MB machine and listen to the fixed disk
    (or, more likely, a hard drive, since this wasn't happening on real IBM
    computers with real IBM fixed disk adapters/A) thrash like crazy.

    Nonetheless, here it is. It is based on IBM2ADSK.ADD from the OS/2 DDK
    and WDCTRL from the Windows 3.1 DDK. So far, testing has been really
    thorough: I tested it on 86Box with a Type 2 Model 80, ESDI adapter
    card, PC DOS 3.30, 4MB and 2MB configurations, Windows 3.1. A test suite >>> program is included which tries to really exercise the disk and get
    Windows' multitasking really crankin' with a couple DOS windows open.

    Download it for yourself at:
    https://github.com/sbooks-org/ABIOSDSK386
    Direct link for 720kB floppy image, because how else would you get it on >>> your PS/2?
    https://github.com/sbooks-org/ABIOSDSK386/releases/download/v0.90/ABIOSDSK.IMG

    No warranty is implied, particularly given this is the kind of code
    whose failure mode will mean you get to reformat your fixed disk and
    reinstall everything.

    I plan to do SCSI support next (it's easier than it sounds; it's just
    another ABIOS interface). Can someone remind me what the state of
    Windows 95 support for ABIOS disk adapters (MFM, ESDI, etc.) and the
    PS/2 SCSI adapter is?



    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Louis Ohland@ohland@charter.net to comp.sys.ibm.ps2.hardware on Sat Aug 8 07:03:31 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    Someone has to fill in for our missing pedantic Brit.

    My understanding is the DBA-ESDI isn't ESDI. Chances are that IBM
    appropriated "ESDI", trying to spiff-up the Integrated Drive used on the
    50z, 70, P70, and the early Model 90 [infamous -402].

    My dark, inscrutable goal is to use the DBA-ESDI sockets for plug-in IDE controllers. My kontuzion lies in the fact that the Integrated Drive has
    it's own BIOS [or so I think], so the system doesn't need to support the DBA-ESDI drive... ?

    IBM DBA-ESDI Hard Drives
    https://ardent-tool.com/storage/DBA_ESDI.html

    Direct Bus Attachment Pinout https://ardent-tool.com/storage/DBA_ESDI.html#Pinout

    PS. Yes, the DBA-Socket is a stripped-down 16-bit slot. IIRC, it lacks
    DMA. -BUT- it exists... The 50/70/90 were designed as a cable-less
    systems. Some kompromises as to storage speed, but a PIO device on the DBA-ESDI _should_ have comparable performance to the stock DBA-ESDI.


    Josh Rodd wrote:
    Presenting ABIOSDSK.386: 32-bit disk access finally gets here for your
    PS/2 with gigantic, clanking MFM drives and irreplaceable ESDI drives.

    This has been about 35 years in coming, ever since as a sprightly 11
    year old I was miffed that my fancy PS/2 P70 just wouldn't let me click
    the "32-bit Disk Access", despite me barely understanding what was even
    for. Of course, we now know that that means you can do things like open
    a couple DOS windows on your 2MB machine and listen to the fixed disk
    (or, more likely, a hard drive, since this wasn't happening on real IBM computers with real IBM fixed disk adapters/A) thrash like crazy.

    Nonetheless, here it is. It is based on IBM2ADSK.ADD from the OS/2 DDK
    and WDCTRL from the Windows 3.1 DDK. So far, testing has been really thorough: I tested it on 86Box with a Type 2 Model 80, ESDI adapter
    card, PC DOS 3.30, 4MB and 2MB configurations, Windows 3.1. A test suite program is included which tries to really exercise the disk and get
    Windows' multitasking really crankin' with a couple DOS windows open.

    Download it for yourself at:
    https://github.com/sbooks-org/ABIOSDSK386
    Direct link for 720kB floppy image, because how else would you get it on
    your PS/2? https://github.com/sbooks-org/ABIOSDSK386/releases/download/v0.90/ABIOSDSK.IMG

    No warranty is implied, particularly given this is the kind of code
    whose failure mode will mean you get to reformat your fixed disk and reinstall everything.

    I plan to do SCSI support next (it's easier than it sounds; it's just
    another ABIOS interface). Can someone remind me what the state of
    Windows 95 support for ABIOS disk adapters (MFM, ESDI, etc.) and the
    PS/2 SCSI adapter is?

    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Josh Rodd@joshua.at.rodd.dot.us@rodd.us to comp.sys.ibm.ps2.hardware on Sat Aug 8 14:27:00 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    Thank you. My understanding is they are "true" IDE - they might have
    some ESDI electronics IBM had lying around and "present" as the ESDI controller, but, well, they're just like ATA, except this isn't an ATA attachment, it's an MCA attachment. Perhaps it should be called MCAA.

    It certainly does carry DMA - see the "ARB" pins. The IBM MFM and ESDI controllers both used DMA (unlike inferior designs found in ISA
    machines), and as attested by how my driver has to be careful not to run
    into the usual "DMA in protected mode" type of problems.

    Ultimately the McIDE controller could probably be adapted to this socket
    - however, the McIDE does *not* present IBM ESDI/A or IBM MFM/A... and
    there's no way to get a ROM in the DBA socket. I don't see anywhere that responds to memory. I mean, I guess it could respond to 16-bit memory
    acccesses and put ROM in the first 64KB of memory... not useful.

    Louis Ohland <ohland@charter.net> wrote:
    Someone has to fill in for our missing pedantic Brit.

    My understanding is the DBA-ESDI isn't ESDI. Chances are that IBM appropriated "ESDI", trying to spiff-up the Integrated Drive used on the 50z, 70, P70, and the early Model 90 [infamous -402].

    My dark, inscrutable goal is to use the DBA-ESDI sockets for plug-in IDE controllers. My kontuzion lies in the fact that the Integrated Drive has it's own BIOS [or so I think], so the system doesn't need to support the DBA-ESDI drive... ?

    IBM DBA-ESDI Hard Drives
    https://ardent-tool.com/storage/DBA_ESDI.html

    Direct Bus Attachment Pinout https://ardent-tool.com/storage/DBA_ESDI.html#Pinout

    PS. Yes, the DBA-Socket is a stripped-down 16-bit slot. IIRC, it lacks
    DMA. -BUT- it exists... The 50/70/90 were designed as a cable-less
    systems. Some kompromises as to storage speed, but a PIO device on the DBA-ESDI _should_ have comparable performance to the stock DBA-ESDI.


    Josh Rodd wrote:
    Presenting ABIOSDSK.386: 32-bit disk access finally gets here for your
    PS/2 with gigantic, clanking MFM drives and irreplaceable ESDI drives.

    This has been about 35 years in coming, ever since as a sprightly 11
    year old I was miffed that my fancy PS/2 P70 just wouldn't let me click
    the "32-bit Disk Access", despite me barely understanding what was even for. Of course, we now know that that means you can do things like open
    a couple DOS windows on your 2MB machine and listen to the fixed disk
    (or, more likely, a hard drive, since this wasn't happening on real IBM computers with real IBM fixed disk adapters/A) thrash like crazy.

    Nonetheless, here it is. It is based on IBM2ADSK.ADD from the OS/2 DDK
    and WDCTRL from the Windows 3.1 DDK. So far, testing has been really thorough: I tested it on 86Box with a Type 2 Model 80, ESDI adapter
    card, PC DOS 3.30, 4MB and 2MB configurations, Windows 3.1. A test suite program is included which tries to really exercise the disk and get Windows' multitasking really crankin' with a couple DOS windows open.

    Download it for yourself at:
    https://github.com/sbooks-org/ABIOSDSK386
    Direct link for 720kB floppy image, because how else would you get it on your PS/2? https://github.com/sbooks-org/ABIOSDSK386/releases/download/v0.90/ABIOSDSK.IMG

    No warranty is implied, particularly given this is the kind of code
    whose failure mode will mean you get to reformat your fixed disk and reinstall everything.

    I plan to do SCSI support next (it's easier than it sounds; it's just another ABIOS interface). Can someone remind me what the state of
    Windows 95 support for ABIOS disk adapters (MFM, ESDI, etc.) and the
    PS/2 SCSI adapter is?



    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Josh Rodd@joshua.at.rodd.dot.us@rodd.us to comp.sys.ibm.ps2.hardware on Sat Aug 8 14:33:07 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    Louis Ohland <ohland@charter.net> wrote:
    From a cursory surf, I'd say no.

    My SWAG would be looking at the NT miniport... Not what you wandted to hear...

    It has been around 29 years since I engaged in the dark art of NT
    programming as a young intern for the remnants of a once-great American manufacturer, now splattered around the world like a nebula after a supernova... and, indeed, I was once spending lots of time studying blue screens, attaching kernel debuggers, and even restarting the kernel -
    and all this on PS/2 P75 (the system under test). It had an 8MB Cumulus
    card, which was unreliable in the P75 (they probbably only tested it on
    Model 70/80 386) and would caused random memory errors after a few
    hours, which perfectly duplicated problems happening in the field.

    At this point, WFW3.11 and whatever came before is what fascinates me.
    Other quixotic quests on deck are building a PC/AT BIOS with ABIOS
    support; 32-bit disk access for the PS/2 SCSI adapter; getting AIX PS/2 actually usable in 86Box; fixing the problems where BASIC/BASICA don't
    work in a Win 386 Enhanced DOS box; and, of course, improving the Mod. 50/60/70/80 BIOSes as discussed previously.
    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Louis Ohland@ohland@charter.net to comp.sys.ibm.ps2.hardware on Sat Aug 8 09:44:06 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    Looking at the DBA-ESDI header pin-out, A30 is -TC

    Huh.

    Josh Rodd wrote:
    Thank you. My understanding is they are "true" IDE - they might have
    some ESDI electronics IBM had lying around and "present" as the ESDI controller, but, well, they're just like ATA, except this isn't an ATA attachment, it's an MCA attachment. Perhaps it should be called MCAA.

    It certainly does carry DMA - see the "ARB" pins. The IBM MFM and ESDI controllers both used DMA (unlike inferior designs found in ISA
    machines), and as attested by how my driver has to be careful not to run
    into the usual "DMA in protected mode" type of problems.

    Ultimately the McIDE controller could probably be adapted to this socket
    - however, the McIDE does *not* present IBM ESDI/A or IBM MFM/A... and there's no way to get a ROM in the DBA socket. I don't see anywhere that responds to memory. I mean, I guess it could respond to 16-bit memory acccesses and put ROM in the first 64KB of memory... not useful.

    Louis Ohland <ohland@charter.net> wrote:
    Someone has to fill in for our missing pedantic Brit.

    My understanding is the DBA-ESDI isn't ESDI. Chances are that IBM
    appropriated "ESDI", trying to spiff-up the Integrated Drive used on the
    50z, 70, P70, and the early Model 90 [infamous -402].

    My dark, inscrutable goal is to use the DBA-ESDI sockets for plug-in IDE
    controllers. My kontuzion lies in the fact that the Integrated Drive has
    it's own BIOS [or so I think], so the system doesn't need to support the
    DBA-ESDI drive... ?

    IBM DBA-ESDI Hard Drives
    https://ardent-tool.com/storage/DBA_ESDI.html

    Direct Bus Attachment Pinout
    https://ardent-tool.com/storage/DBA_ESDI.html#Pinout

    PS. Yes, the DBA-Socket is a stripped-down 16-bit slot. IIRC, it lacks
    DMA. -BUT- it exists... The 50/70/90 were designed as a cable-less
    systems. Some kompromises as to storage speed, but a PIO device on the
    DBA-ESDI _should_ have comparable performance to the stock DBA-ESDI.


    Josh Rodd wrote:
    Presenting ABIOSDSK.386: 32-bit disk access finally gets here for your
    PS/2 with gigantic, clanking MFM drives and irreplaceable ESDI drives.

    This has been about 35 years in coming, ever since as a sprightly 11
    year old I was miffed that my fancy PS/2 P70 just wouldn't let me click
    the "32-bit Disk Access", despite me barely understanding what was even
    for. Of course, we now know that that means you can do things like open
    a couple DOS windows on your 2MB machine and listen to the fixed disk
    (or, more likely, a hard drive, since this wasn't happening on real IBM
    computers with real IBM fixed disk adapters/A) thrash like crazy.

    Nonetheless, here it is. It is based on IBM2ADSK.ADD from the OS/2 DDK
    and WDCTRL from the Windows 3.1 DDK. So far, testing has been really
    thorough: I tested it on 86Box with a Type 2 Model 80, ESDI adapter
    card, PC DOS 3.30, 4MB and 2MB configurations, Windows 3.1. A test suite >>> program is included which tries to really exercise the disk and get
    Windows' multitasking really crankin' with a couple DOS windows open.

    Download it for yourself at:
    https://github.com/sbooks-org/ABIOSDSK386
    Direct link for 720kB floppy image, because how else would you get it on >>> your PS/2?
    https://github.com/sbooks-org/ABIOSDSK386/releases/download/v0.90/ABIOSDSK.IMG

    No warranty is implied, particularly given this is the kind of code
    whose failure mode will mean you get to reformat your fixed disk and
    reinstall everything.

    I plan to do SCSI support next (it's easier than it sounds; it's just
    another ABIOS interface). Can someone remind me what the state of
    Windows 95 support for ABIOS disk adapters (MFM, ESDI, etc.) and the
    PS/2 SCSI adapter is?



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  • From Josh Rodd@joshua.at.rodd.dot.us@rodd.us to comp.sys.ibm.ps2.hardware on Sat Aug 8 14:55:03 2026
    From Newsgroup: comp.sys.ibm.ps2.hardware

    Louis Ohland <ohland@charter.net> wrote:
    Looking at the DBA-ESDI header pin-out, A30 is -TC

    Huh.

    A34 is M/-IO, , but with only A0-A15, it wouldn't be able to be a memory
    slave for anything other than 0-64K.

    The DBA ESDI card (for the 50Z?) had ROM on it, probably for this exact
    reason.

    Note that if you design a CompactFlash, etc. adapter for this, as long
    as it does translation to "speak" ESDI or MFM, the PS/2's BIOS will
    support it. This would be harder than it sounds since that means DMA.
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